Lookback - December 01, 2012
November 2012 Lookback
Widespread flooding fourth week

By Philip Eden


Pressure was substantially below normal (by 4 to 6 mbar) in all parts of the UK during November. There were short anticyclonic spells in the south on the 6th-7th and the 12th-15th, but for the rest of the time the weather was generally cyclonic. Rain was particularly heavy and prolonged between the 20th and 27th, and this triggered repeated flooding in several regions.


Mean maximum temperature during November ranged from 11.5°C at Weymouth (Dorset) to 6.0°C at Dalwhinnie (Inverness-shire), while mean minimum temperature varied between 8.3°C at St Mary's (Isles of Scilly) and 0.0°C at Aboyne (Aberdeenshire). Daytime temperatures were typically 0.5-1.5 degC below the 1981-2010 normal, whereas night-time temperatures were between 0.0 and 1.0 degC below in all regions. The Central England Temperature (CET) of 6.6°C was 0.6 degC below the long-term mean - the lowest in November only since 2010. In the last 100 years 43 Novembers were colder, 52 were warmer, and five had the same mean temperature.


The highest maximum at a standard site (i.e excluding rooftop and mountain sites) in the UK was 16.4°C recorded at Kew Gardens (London) on the 13th, while the lowest minimum was minus 7.3°C Braemar (Aberdeenshire) early on the 29th. The lowest daytime maximum was minus 0.1°C at Castlederg (Co Fermanagh) on the 25th, while the warmest night was that of 19th/20th with a minimum of 12.5°C at Plymouth (Devon).


Rainfall averaged over England and Wales (including a small estimated figure for the 30th) during November was 134mm which is 128 per cent of the average for the standard reference period 1981-2010. Averaged nationally, it was the wettest November only since 2009; however, in the last 100 years just 20 Novembers were wetter while 80 were drier. The equivalent figures for Scotland were 102mm and 86 per cent of the normal amount, and for Northern Ireland 73mm and 80 per cent. Monthly totals at routinely-available sites varied between 319mm at Cluanie Inn (Wester Ross) and 23mm at Kinloss (Morayshire). The heaviest daily fall was 75mm on the 24th at Culdrose (Cornwall), while 177mm fell over the seven-day period 19th-25th at East Okement Farm, near Okehampton (Devon).


Sunshine averaged over England and Wales (including an estimated figure for the 30th) during November was 77 hours which is 110 per cent of the 1981-2010 mean, making this the sunniest November since 2006. In the last 100 years, just 17 Novembers were sunnier while 83 were duller. The equivalent figures for Scotland were 69 hours and 119 per cent, and for Northern Ireland 77 hours and 127 per cent. Largest total in the UK was 91 hours at East Malling (Kent) and the smallest was 38 hours at Kinlochewe (Wester Ross).


Strongest winds during November occurred on the 22nd with gusts to 75 knots at Capel Curig (Caernarfon).


By Philip Eden


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